Infeed control device



Jan' 5 1960 H. ALLEMANN ETAL 2 919 520 INFEED CONTROL DEVICE Filed March 4, 1957' 2 Sheets-Sheet 1 izwg ml I9 19 f6 2 fm eman' W /fie Jan. 5, 1960 ALLEMANN ET AL 2,919,520

INFEED CONTROL DEVICE Filed March 4, 1957 2 Sheets-Sheet 2 Fifi-E "Wt! IIIIIIIIIIIIIQI A l- I1 u in 1 Fig.6

I" I 26 Ti INVENTORS W10 INFEED CONTROL DEVICE Application March 4, 1957, Serial No. 643,879

Claims priority, application Switzerland March 2, 1956 7 Claims. (Cl. 51-165) The present invention refers to grinding machines and more particularly to a transverse feed device for grinding machines, especially suitable for internal grinders.

Up to now it was customary to carry out the transverse or cross feed in a grinding machine, particularly internal grinders, by hand which necessitated a continuous personal attendance by the operator.

It. is a main object of the invention to provide an automatic transverse feed or infeed device which eliminates continuous attendance by an operator and besides results in greater uniformity in the cross feed whereby particularly internal grinding operations are made much more economical and eflicient.

It is another object of the invention to provide a transverse or infeed device which can be mounted equally on the cross slide of a lathe together with an internal grinding device which includes some control device for the traverse feed of the grinding spindle in axial direction, as well as on regular internal grinding machines.

With the above objects in view, a grinding machine according to the invention includes wheel carrier means and work carrier means, one of said carrier means being adapted to carry out reciprocating traverse movements between end positions thereof with respect to the other one of said carrier means, and power means for creating power impulses for reciprocatingly moving one of said carrier means between its end position; the machine further includes infeed means for moving one of the carrier means in a direction transverse to said traverse movement, operating means for stepwise movement of .the infeed means, and actuating means controlled by said power means and actuating said operating means in such a manner as to actuate them in timed relation to the reciprocating traverse movements of one of the carrier means.

In another aspect of this invention infeed means are provided for grinding machines having wheel carrier means and work carrier means as set forth in the preceding paragraph, one of the carrier means being adapted for movement in a direction transverse to the traverse movement of one of the carriers. The infeed means comprise a turnable control spindle for moving one of the carrier means in said transverse direction, operating means for turning the control spindle, including a cylinder adapted to be supplied with a fluid under pressure and an operating piston movable by introduction of the fluid in said cylinder between a starting position and an end position, and drive means for converting a movement of said piston from its starting position to its end position into a turning movement and for imparting to the control spindle with every such movement of the piston a corresponding turning movement. The infeed device further includes means for introducing a fluid under pressure into the cylinder so as to create a pressure impulse for actuating said operating means and for operating the control spindle.

It is to be understood that in the'following specifica- United States Patent tion and claims the term fluid-operated means includes hydraulic means as well as pneumatic means.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a plan view of one embodiment of the invention showing the general disposition of the cooperating elements;

Fig. 2 is a cross-section through the housing of the device shown in Fig. 1, the section being taken along line A-B of Fig. 1;

Fig. 3 is a diagrammatical illustration of an auxiliary control device which is operated by the means controlling the reversal of the traverse movements of the grinder spindle and is mounted together with the latter in a common housing;

Fig. 4 is a fragmentary section through a valve forming part of the auxiliary control device, the section being taken along the line CD of Fig. 3;

Fig. 5 is a diagrammatic sectional view of a grinding device showing part of the control means and actuating means; and

Fig. 6 is a similar diagrammatic sectional view of the same grinding device showing other parts of the control and actuating means.

Referring to Figs. 1 and 2, a ratchet wheel 1 is rigidly connected with the transverse feed spindle 4 between ring member 2 and nut 3. A housing 6 is attached to a flange of a bearing member 5 which supports the spindle 4. On one side of the housing 6 is mounted an inlet member 7 which serves for admitting to the cylinder 6 compressed air derived from the control device of the traverse feed of the spindle shown in Figs. 5 and 6.

A piston 8 is mounted in the housing 6 together with a hydraulic cushioning device acting like a dashpot for piston 8. In the forward end of the piston 8 a pawl 9 is mounted for turning movement about a pivot 9", in such a manner that the pawl 9 is adapted to engage the ratchet teeth of the wheel 1 whereby an operational connection is established between the piston 8 and the feed spindle 4. A compression spring 10 lodged in a longitudinal bore of the piston 8 acts against the rear end of a movable pin 11, which in turn engages a projecting nose 9 of the pawl 9. In case it is desired to make this infeed device inoperative, the pawl 9 may be tilted upward into the position shown in dotted lines in which case the projection 9 passes by and slips under the free end of the spring supported pin 11 so that the pawl 9 is then held in this inoperative position. The axial stroke of the piston 8 can be adjusted by means of an adjustment screw 12. In this manner the amount of feed for every stroke of the piston 8 can be set.

The hydraulic piston 13 having two end portions joined by a central portion of reduced diameter is movably arranged in a second cylinder or bore of the housing 6 and the lower end portion thereof is supported by a spring 14 so that the upper end portion tends to move forward into a recess with an inclined surface portion 8 on one side of the pressure piston 8. The upper end portion of the piston 13 has an inclined surface portion 13' and a ball or roller 15 is interposed between these inclined surfaces 8' and 13' which are substantially parallel to each other. Due to this arrangement the piston 13 is always in operative engagement with the piston 8 through the above ball or roller 15. Whenever the air operated piston 8 makes a forward stroke, the inclined surface 8' of the lateral recess of the piston 8 and the inclined surface spindle has made six strokes.

13 at the end of the piston 13, through the intermediary of the ball 15 cooperate in such a manner that the piston 13 is moved backward against the action of the spring 14 whereby oil or another suitable liquid in the cylinder space about the spring 14 in which the lower end portion of the piston 13 operates is forced to pass between the wall of the cylinder and the lower end portion of piston 13 and is then released through asmall opening 16' into a receiving chamber 16. The passage under force of the liquid between the piston and cylinder wall acts as a cushioning or dampening means so as to slow down the movement of the piston 8 to a predetermined velocity. The just described arrangement also serves to limit the forward stroke of piston 8.

The control device illustrated by Fig. 3 serves to cause the piston 8 to make a forward movement only after a certain number of traverse movements of the grinder spindle in axial direction have been carried out. A valve member 17 of the rotary type with one cross bore 17 is provided with a ratchet wheel 17 which cooperates with a pawl 19 attached to a second piston 18 movable in a second cylinder 18' against a spring 23. A spring 19' tends to keep the ,pawl 19 in engagement with the ratchet wheel 17".

The piston 18 is operated by compressed air which is in turn controlled by a suitable valve, not shown, which is part of and controlled by the means which cause the traverse movement of the grinder spindle to change its direction, so that the valve 17 is moved by the action of the pawl 19 in angular steps corresponding each to one tooth of the ratchet wheel 17". If for instance the ratchet wheel 17" has 12 teeth then a connection of the source of the compressed air operating the grinding machine with the above mentioned piston 8 through the conduits 2t) and 21 is established every time after the grinder The inlet 22 connects the cylinder 18' to the valve means controlling the traverse of the grinder spindle.

The valve 17 with the bore 17' formed therethrough constitute therefore part of an actuating means movable through a predetermined distance to an actuating position where said actuating means actuates the second moving means, that is, the feed spindle 4 which in turn cooperates with one of the carrier means for moving the same through a given feeding stroke. The ratchet wheel 17" and the ratchet pawl 19 and piston 18 operating the same constitute part of the means responsive to reciprocation of the reciprocating first carrier to move the actuating means only through a fraction of the aforementioned predetermined distance during each reciprocating cycle of the first carrier.

It should be understood that the valve 17 can be operated also in a manner different from that described above, for instance a stepwise turning movement of the valve member 17 may be obtained by mechanical operating means which are directly or indirectly connected to parts moving with the grinder spindle in its reciprocating travel.

In the preceding paragraphs it has been stated that power impulses are applied to the piston 8 in the embodiment shown by Figs. 1 and 2, and to the piston 18, respectively, shown in Fig. 3. These power impulses are derived from the power means which serve to reciprocatingly move the spindle carrier or the work carrier of the grinding machine between two end positions. More specifically, these power impulses may be obtained from the control means controlling the reciprocating traverse movement of one of the carriers.

Figs. and 6 show, by way of example, power means and control means used in connection with the traverse movement of a spindle carrier.

Figs. 5 and 6 illustrate one grinding device, only for the sake of clarity the various control and operating means are shown diagrammatically in two different sections of the device.

The grinding device shown is of the type known as internal grinding device and adapted to be mounted as a unit for instance on the cross slide of a lathe. In a housing block is mounted a spindle carrier 103 for sliding movement in its axial direction. The spindle carrier surrounds the grinding spindle 104 which is connected at its rear end with an air turbine arranged inside a housing 105. The spindle carrier 103 is rigidly connected by a rod 27 to a main piston 26 which is movable between end positions in a corresponding bore or main cylinder of the housing block.

Compressed air is introduced by an inlet 112 into a chamber 113 which is connected by a duct 115 to a chamber 119 surrounding a main valve 114 and to a chamber 116 surrounding a control valve 107. Fig. 5 shows the device in a position in which the spindle carrier 103 is in its rearward end position. The turbine housing 105 has a projecting lug 106 adapted to engage adjustable collars 108 and 109, respectively, mounted on an extension of the valve stem 107. In the position shown in Fig. 5 the lug 106 has engaged the collar 108 and thereby moved the control valve 107 together with the spindle carrier 103 into its rearward end position. In this position, the compressed air can flow from the chamber 116 through a groove 117 in the valve 107 and through a duct 118 in the housing block into the space behind one end of the main valve 114. Hereby, the main valve 114 is forced to the right, as seen and shown in Fig. 5, so that the compressed air in the chamber 119 can flow through the groove120 in the main valve 114 and through a duct 121 of the housing block into the main cylinder 122, and more specifically into the space behind the left end of the main piston 26. While the main valve 114 was moved to the right, the air contained in the space in front of the right-hand end of the valve 114 was permitted to .escape through a duct 123 in the housing block and through a transverse bore 24 in the control valve 107 into a silencer chamber 25.

The air introduced into the main cylinder 122 forces the main piston 26 from the position shown in Fig. 5 in direction towards right, as seen in Fig. 5 whereby the spindle carrier 103, as shown in Fig. 6, is carried along by means of a connecting rod 27 and likewise moved in a forward traverse stroke towards the right. The air that was contained in the right-hand portion of the main cylinder 122 is permitted to flow through a duct 28 in the housing block, through the transverse bore 29 of the main valve 114 and through a duct 30, shown in dotted lines, into the silencer chamber 25.

Shortly before the spindle carrier 103 reaches its righthand end position the lug 106 engages the collar 109 so that the control valve 107 is also moved in direction to the right. Now, the compressed air from the chamber 116 flows through the grooves 117 of the control valve 107 and through the duct 123 into the opposite end of the bore containing the main valve 114 and moves the latter in direction to the left. When the valve 114 is in its left-hand position, the air from chamber 119 flows through the groove 120 of the main valve 114 and through the duct 128 into the space at the right-hand end of the main cylinder 122 whereby the main piston 26 is returned to its previous position at the left-end of the main cylinder 122, the spindle carrier 103 being hereby also moved back into the previous position as shown in Figs. 5 and 6. This movement towards left continues until the lug 106 engages the collar 108 shortly before the spindle carrier 103 reaches its end position. As soon as the control valve 107 reaches its lefthand end position the whole cycle as described repeats.

It is evident that for instance in the bore of the control valve 107 periodic pressure impulses occur every time when the spindle carrier reaches one of its end positions. The same applies to the bore of the main control valve 114. Therefore, if the just-mentioned control valves or rather their bores are connected either to the inlet 7 of the device shown in Fig. 1, or to the inlet 22 of the device shown in Fig. 3, pressure impulses will be applied to the infeed device in timed relation with the reciprocating traverse movements of the spindle carrier. Arrangements can be made easily in such a way that an impulse is transmitted to the infeed device only when the spindle carrier has completed either its forward traverse or its return traverse, or at the completion of either stroke.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of infeed means differing from the types described above.

While theinvention has been illustrated and described as embodied in infeed means for grinding machines, it is'not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characterisitcs of the generic or specific aspects of this invention, and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a machine tool having a structure for carrying work and a tool for movement one with respect to the other, said structure including first and second carrier means, said first carrier means reciprocating repeatedly through cycles of movement each of which includes a reciprocation of said first carrier means along a given path away from and back to a starting position and one of said carrier means being movable in a direction transverse to said path, in combination, first moving means cooperating with said first carrier means for reciprocating the same through said cycles of movement; second moving means cooperating with said one carrier means for moving the same through a given feeding stroke in said transverse direction; actuating means movable through a predetermined distance to an actuating position where said actuating means actuates said second moving means to feed said one carrier means; and means responsive to reciprocation of said first carrier means to move said actuating means only through a fraction of said predetermined distance during each reciprocating cycle of said first carrier means.

2. In a machine tool as recited in claim 1, said second moving means being operated by fluid under pressure and said means responsive to reciprocation of said first carrier means cooperating with said first moving means to receive therefrom a fluid pressure impulse at least once during each of said cycles of said movement, said actuating means including a body formed with an elongate passage one end of which communicates with a source of fluid under pressure and the other end of which communicates with said second moving means to transmit said fluid under pressure thereto, said actuating means including a valve means interrupting and closing said passage to prevent said fluid under pressure from being transmitted to said second moving means until said valve means is moved through a predetermined distance to an open position, and said means responsive to reciprocation of said first carrier means cooperating with said valve means to move said valve means only through a fraction of said predetermined distance during each reciprocating cycle of said first carrier means.

3. In a machine tool as recited in claim 2, said valve means including a valve body formed with a bore passing therethrough and movably carried by said body formed with said passage for movement to an open position where said bore is aligned with said passage.

4. In a machine tool as recited in claim 3, said valve body being in the form of a member extending across said passage between the ends thereof and turnable about its axis to a position where said bore is aligned with said passage, a ratchet wheel fixed to said valve body, a pawl cooperating with said ratchet wheel, a piston slidably supported by said body formed with said passage in a cylindrical bore of the latter body which communicates with said first moving means to receive said fluid pressure impulse therefrom, said piston carrying said pawl to turn said ratchet wheel and said valve body therewith, each time a fluid pressure impulse is transmitted to said piston, through an angular distance less than that required to turn said valve body from said open position thereof through a closed position and back to said open position.

5. In a machine tool as recited in claim 4, at least said ratchet wheel being replaceable by another ratchet wheel with a different number of teeth for changing the number of cycles between each feeding stroke.

6. In a machine tool having a structure for carrying a work piece and a tool for movement one with respect to the other, such structure including first and second carrier means, said first carrier means reciprocating along a given path away and back to a starting position and one of said carrier means being movable in a direction transverse to said path, in combination, a turnable control spindle for moving one of said carrier means in a direction transverse to said path; bearing means supporting said spindle adjacent to one end thereof; operating means for turning said spindle and including a ratchet wheel fixedly mounted on said spindle, an elongated housing mounted on said bearing extending laterally therefrom and being formed with a bore extending in longitudinal direction of said housing, a piston reciprocatably mounted in said bore, a ratchet pawl carried on one end of said piston and cooperating with said ratchet wheel for turning the same step by step during the reciprocation of said piston, passage means communicating with said bore on one side of said piston and adapted to feed air under pressure into said bore so as to move said piston in one direction, and spring means operatively connected to said piston to move said piston in a direction opposite to said one direction; and fluid operated dampening means operatively connected to said piston for a dampening movement of said piston in both directions.

7. An arrangement as defined in claim 6 and including adjustable means closing said bore at one end to limit the stroke of said piston in one direction, said means being adjustable in longitudinal direction of said bore so as to adjust the stroke of said piston in said one direction and said fluid operated dampening means cooperating with said piston to limit the stroke thereof in the other direction.

References Cited in the file of this patent UNITED STATES PATENTS Morgan June 21, 1927 

